The present invention relates to a system (method and apparatus) for wound closure, and in particular to a system for vascular wound closure utilizing a tissue suturing apparatus and a suture securing apparatus. The invention is suitable for applying at least one suture to close a wound, such as a puncture hole in a blood vessel, after an intravascular catheterization procedure. The invention is also suitable for applying a suture to a wound in other bodily tissue, such as the bowel. The term wound generally refers to herein to a hole, puncture, or any opening in tissue requiring closure.
When performing catheterization procedures, such an angiography or angioplasty, a catheter is generally introduced percutaneously (i.e., through the skin) into the vascular system by first penetrating the skin and underlying tissue, and then the blood vessel with a sharpened hollow needle. Location of a blood vessel, such as an artery, is typically achieved by feeling for the pulse, since such structures usually cannot be seen through the skin. Next, a guide wire is commonly inserted through the lumen of the hollow needle and is caused to enter the selected blood vessel. Subsequently, the needle is typically slid off the guide wire and a combination of a dilator and sheath are fed over the guide wire and pushed through the skin to enter the vessel. The guide wire and dilator can then be removed and the desired catheter to carry out the procedure is fed through the lumen of the sheath and advanced through the vascular system until the working end of the catheter is appropriately positioned. Following the conclusion of the catheterization procedure, the working catheter will be withdrawn and, subsequently, the sheath can also be removed from the wound, or left in place to facilitate closure.
At this point in the procedure, the vessel leakage must be controlled in order to stem the flow of blood through the puncture. Because it is common practice to administer a blood thinning agent to the patient prior to many of the catheterization procedures, stemming the blood flow can be troublesome. A common method of sealing the wound is to maintain external pressure over the vessel until the puncture naturally seals. This method of puncture closure typically takes at least thirty minutes, with the length of time usually being substantially greater if the patient is hypertensive or anti-coagulated. In some anti-coagulated patients, the sheath is left in place for hours to allow the anti-coagulant to wear off. When human hand pressure is utilized, it can be uncomfortable for the patient and can use costly professional time on the part of the hospital staff. Other pressure techniques, such as pressure bandages, sandbags or clamps, have been employed, but these devices also require the patient to remain motionless for an extended period of time and the patient must be closely monitored to ensure their effectiveness.
Other devices have been disclosed which plug or otherwise provide an obstruction in the area of the puncture. See, for example, U.S. Pat. Nos. 4,852,568 and 4,890,612, wherein a collagen plug is disposed in the blood vessel opening. When the plug is exposed to body fluids, it swells to create a block for the wound in the vessel wall. A potential problem of plugs introduced into the vessel is that particles may break off and float downstream to the point where they may lodge in a smaller vessel, causing an infarct to occur. Collagen material also acts as a nidus for platelet aggregation and, therefore, can cause intraluminal deposition of hemostatic agent, thereby creating the possibility of a thrombosis at the puncture sight. Other plug-like devices are disclosed, for example, in U.S. Pat. Nos. 5,342,393, 5,370,660 and 5,411,520.
Surgical clips and clip appliers are known have also been used in vascular surgery, particularly to join severed vessels. For example, U.S. Pat. No. 4,929,240 describes clips generally arcuate in shape, which have two legs that are biased towards each other by clip applier jaws to capture vessel tissue therebetween. While vascular clips have been successfully used in surgery, the surgical procedures in which the clips are typically used allow the surgeon to view the area to be clipped. In catheter puncture repair procedures, however, the wound is generally not visible, making proper clip application, if attempted, difficult.
The use of suturing instruments to close a puncture at the end of a tissue tract is disclosed in U.S. Pat. No. 5,368,601, wherein one of the instruments has a pair of needles, with the tips or points of the needles oriented in a proximal direction, releasably disposed at a distal end thereof. Once in the puncture wound, the instrument is activated to expose the needles. Thereafter, proximal movement of the instrument causes the needles to pass through the wound edge (from the inside to the outside) on either side of the puncture and the needles are withdrawn. A strand of suture material secured between the blunt ends of the needles is also drawn through the needle puncture holes, thereby leaving a span of suture across the hole on the inside of the vessel. The suture can then be tied to close the puncture. A disadvantage to this approach is the potential for needles to deflect in undesirable directions, and the potential difficultly of retrieving the needle tips. Also, the instruments used in this approach are relatively complex, may be unreliable in small sizes, and are costly to manufacture. A similar instrument is also described in U.S. Pat. No. 5,417,699.
Another suturing instrument is described in U.S. Pat. No. 5,431,666 having a pair of longitudinally movable needles to pick up corresponding ends of suture at a distal end of the instrument. A needle capture mechanism provides two needle receiving portions, called ferrules, having a strand of suture material disposed therebetween, which are initially separated from the needles by a single gap in the instrument. In use, tissue to be sutured is disposed in the gap between the needles and the two needle receiving portions called ferrules. A first needle punctures the tissue, engages one end of the suture, and draws it back through the tissue. The instrument can then be relocated to another portion of tissue and the second needle is actuated to pick up and draw the second end of the suture through the tissue. The suture material can then be tied or otherwise cinched in place to secure the tissue closed. In using this instrument, the surgeon is typically able to view the surgical site.
Typically, the user, such as a surgeon or interventional cardiologist, cannot directly view the percutaneous vascular wound that would otherwise facilitate suture placement on opposite sides of the puncture wound. U.S. Pat. No. 5,766,183 describes a suture instrument for vascular wound closure in which the user does not need to view the wound. The suture instrument has a pair of longitudinally movable needles to pick up corresponding suture ends at a distal end of the instrument. As in U.S. Pat. No. 5,431,666, the strand of suture material can have ferrules at each end. To suture the vascular wound, the instrument is placed through a sheath immediately above vascular wound, or through a tissue tract larger than the vascular wound. One side of the tissue near the wound is punctured by a first needle which engages a ferrule and drawn back through the tissue with the ferrule. The instrument is then rotated to puncture the vascular tissue near another side of the wound with a second needle, which engages the other ferrule and drawn back through the tissue with the other ferrule. After the suture is in place, the instrument is withdrawn leaving the suture behind. Another instrument crimps a sleeve member over the free ends of the suture near the wound and cuts the suture such that the wound is secured closed.
One drawback of the suture instrument of the U.S. Pat. No. 5,766,183 is that since the user does not directly view the site of the vascular wound to be closed, it can be difficult for the user after the first needle punctures the tissue to rotate the instrument such that the second needle is properly aligned at a location which will provide a suture capable of maintaining the wound closed. Preferably, the second needle when applied to the tissue is approximately 180 degrees opposite the location where the first needle punctured the tissue, in respect to the puncture wound along a direction longitudinal with the blood vessel. If the suture is not properly placed across the wound, the suture may not completely close the wound. Another potential problem with this approach is the need for the tissue tract to be larger than the vascular wound.
It is therefore desirable to provide surgical techniques and instrumentation for closing wounds in blood vessels which reliably allows a user without viewing the wound to direct a suture at two locations about the wound which does not need instrument rotation to suture and to facilitate maximizing the distance between the suture and the edges of the wound.
Moreover, improved medical equipment is needed to allow suturing instruments to pass through the sheath already in place in the body of a patient to suture a vascular wound.
Accordingly, it is the principal object of the present invention to provide an improved system for closure of a wound in a blood vessel that overcomes the drawbacks of the prior art.
Briefly described, the system embodying the invention includes a first apparatus for applying a suture capable of closing the wound and a second apparatus for securing a sleeve member over the suture to secure the wound closed. The first apparatus includes a housing, a shaft having first and second ends in which the first end is coupled to the housing, a tissue engaging section coupled to the second end of the shaft, and first and second needles which extend from the housing through the interior of the shaft into the tissue engaging section, although the needles could be shorter and their movement through the shaft could be assisted by an additional driving mechanism. The shaft and tissue engaging section may be directed to the wound through a sheath (or cannula) previously inserted in the body of the patient. The tissue engaging section has first and second gaps disposed opposite each other. Each gap has opposing surfaces into which different sides of the wound can be received. The first needle is extendable into the first gap through an opening of the tissue engaging section into a needle capturing portion coupled to one of the ends of a suture material, and is retractable with the captured end of the suture material. The second needle is extendable into the second gap through another opening of the tissue engaging section into another needle capturing portion coupled to the other end of the suture material, and is retractable with the captured end of the suture material. A suture tube in the housing extends through the housing and the shaft to the tissue engaging section, and is loaded with loop of suture material having two ends that extend to the needle capturing portions in the tissue engaging section. A selecting mechanism enables automatic or manual selection of each one of the first and second needles. A user operates an actuator member in the housing to drive and retract the selected needle to locate each end of the suture through the tissue about the wound. After removal of the first apparatus, the suture material is left across the wound and the ends of the suture material extend from the sheath. The second apparatus secures a sleeve member over the two ends of the suture material to maintain the wound closed and then cuts the suture material exiting the secured sleeve member.
The first apparatus may further include a tubule flexible guide section coupled to the tissue engaging section to guide the tissue engaging section through the sheath and wound into the blood vessel over a guide wire previously situated therein, and enable the guide wire to be removed. The shaft of the first apparatus may be circular, or oval in cross-section having a major axis of the oval in a first dimension as its extends from the housing, and then oval in cross-section in a second dimension for at least a substantial portion of the shaft near the tissue engaging section to accommodate the two needles being substantially parallel in a first plane near the housing and then substantially parallel in a second plane orthogonal to the first plane near the tissue engaging section. The oval shape of the shaft enables the needles to have a larger distance apart from each other than would otherwise be provided if the shaft were circular in cross-section. The sheath (or cannula) through which the suture instrument is located to access the wound is generally circular in cross-section and made of a flexible material, such that it can deform to accommodate the oval shaft of the suture instrument.
The suture securing instrument of the system includes a tube extending from a housing to a distal end, and a rod extending through the tube in which the rod has first and second ends. The first end of the rod is coupled to a lever pivotally mounted in the housing to move the rod, while the second end of the rod extends into the chamber of the distal end. The distal end has a chamber into which the tube is received, a receptacle at its tip for receiving a round or oval tubular securing sleeve member, and an opening in chamber through which the two ends of suture material can extended after passing through the sleeve member. The second end of the rod is shaped to have an upper surface that is downwardly sloped to provide a step and then terminates at a hammer shaped section at the tip of the distal end. The hammer-shaped section may be adjacent a sleeve member loaded in the receptacle through a slot at the bottom of the receptacle. When a sleeve member is loaded in the receptacle, the user may pull the lever to retract the rod which enables the hammer-shaped section of the rod to be raised by a ramp located at the bottom of the chamber of the distal end, such that the pressure applied upon the sleeve member by the hammer-shaped section crimps at least part of the sleeve member. A knife is pivotally mounted in the chamber of the distal end, and, responsive to the hammer-shaped section of the rod abutting the knife as the rod is further retracted, rotates the knife upwards to cut the suture material extending from the crimped sleeve member. The suture securing instrument may then be withdrawn through the cannula leaving the crimped sleeve member to maintain the wound closure by the suture.
The invention further includes a method for using the first and second apparatuses to close a vascular wound, and a surgical kit including both the first and second apparatuses as parts of the kit.
One advantage of first apparatus is that it allows a suture to be placed through a sheath and thus, there is no need to expand the diameter of the a puncture wound in order to place a suture across the wound, such as often needed in prior art suturing techniques. A further advantage of the first apparatus is the ability to locate the edges of the wound to be sutured from inside a blood vessel.